BOSTON – Homeowners and motorists dug out across the white-blanketed Northeast on Friday as extreme cold ushered in by the storm threatened fingers and toes but kept the snow powdery and mercifully easy to shovel. At least 15 deaths were blamed on the storm as it swept across the nation’s eastern half.

While the snowfall had all but stopped by morning across the hard-hit Philadelphia-to-Boston corridor and many highways and streets were soon plowed and reopened, temperatures were in the single digits and teens, with wind chills well below zero.

“The snow is easy to move because the air was so cold when it snowed that it’s sort of light and fluffy stuff – but, uh, it’s cold,” Avalon “Nick” Minton said as he cleared the entrance to his garage and sidewalk in Arlington, Mass. “That’s the main part. It’s cold.”

And officials from the Midwest to New England are preparing for another arctic blast in the next few days that could be even worse.

The heaviest snow fell north of Boston in Boxford, which received nearly 2 feet. Nearly 18 inches fell in Boston and in western New York near Rochester. Lakewood, N.J., got 10 inches, and New York’s Central Park 6. Philadelphia got more than 6 inches.

Temperatures reached 8 below zero in Burlington, Vt., with a wind chill of 29 below, and 2 degrees in Boston. Wind chills there and in Providence, R.I., made it feel like minus-20 Friday morning, and the forecast called for more of the same into Saturday.

Emergency officials warned that anyone spending more than a few minutes outdoors in such conditions could suffer frostbite.

Wellington Ferreira said the cold was worse than the snow as he cleared a sidewalk in front of Johnny D’s Uptown Restaurant and Music Club in Somerville.

“My ears are frozen,” he said.

Warming centers opened around the region, homeless shelters received more people, and cities took special measures to look after those most vulnerable to the cold. Teams in New York City searched the streets for homeless people, while in Boston police asked residents to call 911 if they saw someone in need.

In Newport, R.I., the Seaman’s Church Institute said it would stay open around the clock until the cold breaks to give mariners and others who work in or around the harbor a warm place to stay, shower and eat.

The light, powdery snow was a blessing in another respect: It did not weigh down electrical lines or tree limbs, and as a result there were only a few thousand power outages across the Northeast.

Slick roads were blamed for several traffic deaths. In addition, a 71-year-old woman with Alzheimer’s disease froze to death after she wandered away from her rural western New York home. And a worker in Philadelphia was killed when a 100-foot-high pile of road salt fell and crushed him.

Schools as far south as Washington, D.C., were closed on Friday. Many government offices also shut down.

Major highways in and around New York City reopened, and airports across the region struggled to resume normal operations after U.S. airlines canceled around 2,200 flights on Friday on top of 2,300 the day before.

Jeremy Shapiro, 73, of Manhattan, became stranded at New York’s Kennedy Airport on Thursday. On Friday afternoon, he was still holding out hope for a spot flying standby so he could get to Santa Barbara, Calif.

He secured a cot, a pillow and a blanket after seeing about 150 passengers sleeping on cots at the terminal.

“It looked like an infirmary from WWI,” he said.

Severe cold also gripped the Midwest on Friday. In Wisconsin, the mercury dipped to minus-18 in Green Bay, breaking by 1 degree the record set in 1979. Fort Wayne, Ind., saw a record low minus-10. And the mercury sank to 2 below zero at the Detroit airport.

Temperatures in the Midwest and the Northeast are expected to rise briefly over the weekend before the arrival of another blast of extraordinarily cold air.

Minnesota Gov. Mark Dayton ordered school canceled on Monday statewide, the first such closing in 17 years, because of projected highs in the minus teens and lows as cold as 30 below.

The cold air could refreeze roads that are wet or slushy from the weekend thaw, making travel dangerous.

The heavy weather posed the first big test for New York Mayor Bill de Blasio, who was sworn in a day before the heavy snow arrived. De Blasio dispatched hundreds of plows and salt spreaders.

“I feel great about the response,” De Blasio said Friday after shoveling the sidewalk at his Brooklyn home. “We are vigilant. We are not out of this yet. As a great man said, ‘It’s not over until it’s over.”’